class type server_key_verifier =Aobject..end
server_key_verifier verifies on the server side that the users
exist and have the right authentication credentialsmethod scram_credentials : string -> string * string * int (salted_password, salt, iteration_count)
for a user, or raises Not_found. See
Netmech_scram.create_server_session for the meaning of this
triple.